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More Damage :-(

A project log for BorgCube ROV

Underwater robots!

tim-wilkinsonTim Wilkinson 05/04/2016 at 21:210 Comments

After fixing the main PCB last night I had chance to check the rest of the ROV this morning .... and I found the source of the current surge which fried the current resistor.

One of these ESCs is not like the others :-( These are all encased in QSil which means I needed to dig it out. Here it is ... doesn't look good does it.

So what happened? It's difficult to say for sure; ESCs can fail for many reason, including them being cheap and it's what you should expect occasionally. But I'm inclined to think the failure was caused by water. Although the entire board of ESCs is sealer in QSil, examining all the others carefully you can see a hazy grayness around some of the power wires going to the motors; almost as if there's a small air gap forming. I think what's probably happening is that, as the wire warms, the bond between it and the QSill is being broken, and water is getting in. Once the water makes it all the way to the ESC ... KABOOM!!

Rather annoyingly, this means I need to completely rebuild my ESC board. I have two obvious options - (1) reseal the ESCs in something more effective at keeping the water out, or (2) build a different kind of ESC enclosure. Right now, not sure which is best.

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